Liquid filter with an eccentric liquid discharge channel

Abstract

A liquid filter with a replaceable filter insert and a housing having a raw liquid inlet, a central clean liquid outlet, and an eccentric liquid discharge channel. A standpipe extends above the liquid outlet and receives the insert. The insert has an eccentric closing pin. A first positioning arrangement is arranged on the clean liquid outlet and a lower end region of the standpipe so that, when the standpipe is plugged into the clean liquid outlet, the standpipe is guided into a particular position relative to the filter housing. A second positioning arrangement is arranged on the standpipe and the insert so that, when the insert is plugged onto the standpipe, it is guided into a particular position relative to the standpipe. The positioning arrangements are matched to one another so that the closing pin on the insert enters into engagement with the discharge channel in the filter housing.

The invention claimed is:  
     
       1. A liquid filter comprising:
 a filter housing and a filter insert exchangeably situated therein, 
 the filter housing having a raw liquid inlet, a central clean liquid outlet, and an eccentric liquid discharge channel, 
 a central standpipe being situated above the clean liquid outlet, 
 the filter insert being plugged onto the standpipe, 
 the filter insert having an eccentric closing pin on its side facing the liquid discharge channel, and positioning means being arranged such that, when the filter insert is plugged onto the standpipe, the positioning means guide the closing pin into engagement with the eccentric liquid discharge channel, 
 the central standpipe being a separate component that connects to the clean liquid outlet by a plug connection, 
 first positioning means arranged on the central clean liquid outlet and on a lower end region of the standpipe that, when the standpipe is plugged into the clean liquid outlet, guide the standpipe into a particular position in the circumferential direction relative to the filter housing, 
 second positioning means arranged on the outer circumference of the standpipe and on the inner circumference of the filter insert that, when the filter insert is plugged onto the standpipe, guide the filter insert into a particular position in the circumferential direction relative to the standpipe, and 
 the first and second positioning means being matched to one another in such a way that the closing pin on the filter insert enters into engagement with the eccentric liquid discharge channel in the filter housing. 
 
     
     
       2. The liquid filter as recited in  claim 1 , wherein the standpipe, the filter insert, and a filter housing screw cover can be preassembled to form a unit that can be connected as a whole to the filter housing, with automatic positioning of the closure pin and liquid discharge channel, to form the liquid filter. 
     
     
       3. The liquid filter as recited in  claim 2 , wherein on the standpipe and on the filter insert, and on the filter insert and on the filter housing screw cover, in each case a locking means system is provided that can be brought into and out of engagement, of which the locking means system between the filter insert and the filter housing screw cover is a locking means system that transmits torques limited to a specifiable magnitude and that permits a rotation relative to one another. 
     
     
       4. The liquid filter as recited in  claim 1 , wherein the first positioning means are formed at the filter housing side by a tube base having an upper side that runs at least one of obliquely and in stepped fashion and that goes over into an axial slot, and are formed at the standpipe side by a dog that protrudes radially outward. 
     
     
       5. The liquid filter as recited in  claim 1 , wherein the second positioning means are formed at the standpipe side by a pair of guide webs that run symmetrically to one another obliquely downward toward one another, and that go over into an axial slot, and are formed at the filter insert side by a dog that protrudes radially inward. 
     
     
       6. The liquid filter as recited in  claim 5 , wherein the filter insert has a hollow cylindrical filter material body in whose hollow interior there is situated a grid-type supporting body with which the radially inward-protruding dog is one of connected and made in one piece. 
     
     
       7. The liquid filter as recited in  claim 6 , wherein the filter insert has two end plates that enclose the hollow cylindrical filter material body at its ends, and wherein the closing pin is one of, made in one piece with and connected to, one of the end plates. 
     
     
       8. The liquid filter as recited in  claim 1 , wherein the standpipe is perforated at least in the upper half of its height, and wherein a filter bypass valve is situated in an upper end region of the standpipe. 
     
     
       9. The liquid filter as recited in  claim 8 , wherein a valve seat that works together with a valve body of the filter bypass valve is fashioned on an end plate of the filter insert that is an upper end plate in an installed position. 
     
     
       10. The liquid filter as recited in  claim 1 , wherein a no-load blocking valve is situated in or on a lower region of the standpipe. 
     
     
       11. The liquid filter as recited in  claim 10 , wherein a valve body of the no-load blocking valve works together with the lower end, fashioned as valve seat, of the standpipe. 
     
     
       12. The liquid filter as recited in  claim 1 , wherein the standpipe, when it is plugged together with the clean liquid outlet, can be locked or clamped to the filter housing in such a way that when the filter insert is withdrawn from the standpipe, the standpipe remains in the clean liquid outlet.